Light guide plate, backlight module, and display device

ABSTRACT

A light guide plate includes a main body, stripe structures, and light-adjusting structures. The main body includes a light-incident surface and an optical surface. The stripe structures are disposed on the optical surface. The light-adjusting structures are disposed between two adjacent stripe structures. Each of the light-adjusting structures includes a first light active surface and a second light active surface. The first light active surface faces towards the light-incident surface. The second light active surface faces towards an opposite light-incident surface. The first light active surface and the second light active surface are inclined towards different directions and formed a non-symmetrical shape. A first included angle is formed between the first light active surface and the optical surface. A second included angle is formed between the second light active surface and the optical surface. The first included angle and the second included angle are acute angles.

RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 17/322,883, filed on May 17, 2021, which is a continuationapplication of U.S. application Ser. No. 16/830,257, filed on Mar. 25,2020, now Patent No. U.S. Pat. No. 11,035,996, which is acontinuation-in-part application of International Application No.PCT/CN2018/086694 filed on May 14, 2018, which also claims priority fromChina Patent Application Serial Number 201910342677.6, filed on Apr. 26,2019. The entire contents of each of which are incorporated byreference.

BACKGROUND Field of Invention

The present invention relates to a light guide device and itsapplications. More particularly, the present invention relates to alight guide plate and its applications to a backlight module and adisplay device.

Description of Related Art

A light guide plate has a light-incident surface, a light-emittingsurface and a reflective surface. Light provided by a light sourceenters the light guide plate from the light-incident surface, and exitsfrom the light-emitting surface.

Simultaneously referring to FIG. 1A and FIG. 1B, FIG. 1A is a schematicdiagram showing a conventional microstructure 10 of U.S. PatentApplication Publication No. 2015/0346414 A, and FIG. 1B is a schematicdiagram showing an operation of processing a mold for forming themicrostructure shown in the FIG. 1A. The microstructure 10 shown in FIG.1A mainly includes a first optical surface 11, a second optical surface12 and a side portion 13, in which one of the first optical surface 11and the second optical surface 12 faces towards the light-incidentsurface of the light guide plate, and the other one of the first opticalsurface 11 and the second optical surface 12 faces away from thelight-incident surface. Although the design of the microstructure 10 canchange the light emitting angle and light directivity after lightemitted from the light guide plate so as to improve light emittingefficiency and appearance uniformity, some problems still exist in themicrostructure 10 as follows.

For example, as shown in FIG. 1B, during the operation of processing amold M1, a feeding path and a retracting path of a cutting tool K1 haveto be inclined relative to the mold M1 to form the side portion 13 ofthe microstructure 10 with an inclined structure. The side portion 13 ofthe microstructure 10 does not face towards or away from thelight-incident surface of the light guide plate, that is, the sideportion 13 of the microstructure 10 is not in a traveling direction oflight, and thus does not make a contribution to guiding the light toleave the light guide plate. Moreover, because the side portion 13 isdirectly connected to the optical surface (that is a flat surface) ofthe light guide plate, the total internal reflection principle of theoriginal flat surface will not meet, thus causing the light to leak fromthe connection between the side portion 13 and the optical surface ofthe light guide plate. Furthermore, different inclined angles betweenthe first optical surface 11 and the second optical surface 12 cause theside portion 13 to have different slopes and surface areas, and thus thelight-emitting effect of the microstructure 10 is difficult to becontrolled. Moreover, the aforementioned operation of processing themold M1 also takes more processing time.

SUMMARY

The invention provides a light guide plate having microstructures whichdo not cause the light leakage problem, thereby increasing a utilizationrate of light.

According to the aforementioned object, a light guide plate is provided.The light guide plate includes a main body, plural stripe structures,and plural light-adjusting structures. The main body includes alight-incident surface and an optical surface connected to thelight-incident surface. The stripe structures are disposed on theoptical surface. The light-adjusting structures are disposed betweenevery two adjacent stripe structures, in which each of thelight-adjusting structures includes a first light active surface and asecond light active surface connected to the first light active surface.The first light active surface faces towards the light-incident surface,and the second light active surface faces towards a side of the mainbody which is opposite to the light-incident surface. The first lightactive surface and the second light active surface are inclined towardsdifferent directions and formed a non-symmetrical shape, and a firstincluded angle is formed between the first light active surface and theoptical surface, and a second included angle is formed between thesecond light active surface and the optical surface. Each of the firstincluded angle and the second included angle is an acute angle.

According to an embodiment of the present invention, side edges of thefirst light active surface and the second light active surface of eachof the light-adjusting structures are connected to surfaces of thestriped structures adjacent thereto.

According to an embodiment of the present invention, an extendingdirection of each of the striped structures is vertical to an extendingdirection of the light-incident surface.

According to an embodiment of the present invention, the main body hasan opposite light-incident surface which is opposite to thelight-incident surface. One end of each of the striped structures isconnected to the light-incident surface, and the other end of each ofthe striped structures is connected to the opposite light-incidentsurface.

According to an embodiment of the present invention, the first angle isgreater than the second angle.

According to an embodiment of the present invention, the light-adjustingstructures are continuously or non-continuously arranged along thestriped structures.

According to an embodiment of the present invention, the light-adjustingstructures are arranged along the striped structures. Each of thelight-adjusting structures has a size which becomes greater withincreased distance from the light-incident surface.

According to an embodiment of the present invention, the light-adjustingstructures are arranged along the striped structures. Distances betweenany every two adjacent light-adjusting structures decrease along adirection from the light-incident surface to an opposite light-incidentsurface which is opposite to the light-incident surface.

According to an embodiment of the present invention, each of the stripedstructures is a convex structure or a concave structure.

According to an embodiment of the present invention, the optical surfaceis a light-emitting surface or a reflecting surface.

According to an embodiment of the present invention, the stripedstructures are continuously arranged or non-continuously arranged.

According to an embodiment of the present invention, the first lightactive surface and the second light active surface of each of thelight-adjusting structures are continuously arranged along a directionwhich is vertical to the light-incident surface. The first light activesurface and the second light active surface of each of thelight-adjusting structures are connected to form a junction line,wherein the junction line is parallel to the light-incident surface.Each of the first light active surface and the second light activesurface of each of the light-adjusting structures has an end edge andtwo side edges, in which the end edge is parallel to the junction line,and the side edges are not parallel to the junction line, and the sideedges are connected to surfaces of the adjacent striped structures.

According to an embodiment of the present invention, a portion of eachof the light-adjusting structures overlaps with its adjacent stripestructures.

According to an embodiment of the present invention, each of thelight-adjusting structures comprises a first flank portion and a secondflank portion, and the first flank portion and the second flank portionof each of the light-adjusting structures are respectively located attwo opposite sides of the junction line and overlap with their adjacentstripe structures.

According to an embodiment of the present invention, each of the stripestructures has side edges, and a distance between the side edges of twoadjacent stripe structures is the same from one end of each of thestripe structures located near the light-incident surface to the otherend of each of the stripe structures located away from thelight-incident surface.

According to an embodiment of the present invention, each of the stripestructures has side edges, and a distance between the side edges of twoadjacent stripe structures is gradually decreasing from one end of eachof the stripe structures located near the light-incident surface to theother end of each of the stripe structures located away from thelight-incident surface.

According to the aforementioned object, a backlight module is provided.The backlight module includes an aforementioned light guide plate, atleast one film, a reflecting film and a light source. The film isdisposed in front of the light guide plate. The reflecting film isdisposed behind the light guide plate. The light source is disposedadjacent to the light-incident surface of the light guide plate.

According to the aforementioned object, a display device is provided.The display device includes an aforementioned light guide plate, atleast one film, a reflecting film, a light source and a display panel.The film is disposed in front of the light guide plate. The reflectingfilm is disposed behind the light guide plate. The light source isdisposed adjacent to the light-incident surface of the light guideplate. The display panel is disposed in front of the at least one film.

According to the aforementioned embodiments of the present invention,the light guide plate of the present invention has stripe structures andlight-adjusting structures disposed between every two adjacent stripestructures, such that the stripe structures are directly formed as sideportions of the light-adjusting structures, thereby preventing the lightleakage problem on the sides of the conventional microstructures. Inother words, because each of the light-adjusting structures is notdirectly connected to the flat surface of the light guide plate, thelight leakage problem due to the connections between the conventionmicrostructures and the flat optical surface of the light guide plate asdescribed in the “Description of Related Art” can be resolved. Inaddition, the light active surfaces of each of the light-adjustingstructures have different inclinations, which can increase the amount oflight reflection or guide the light, thereby increasing lightutilization efficiency. Because the stripe structures are directlyformed as side portions of the light-adjusting structures, theprocessing time of the light guide plate can be reduced, and theinclination of the light active surfaces can be precisely controlled,thereby achieving required optical effect.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be more fully understood by reading the followingdetailed description of the embodiment, with reference made to theaccompanying drawings as follows:

FIG. 1A is a schematic diagram showing a conventional microstructure ofU.S. Patent Application Publication No. 2015/0346414 A;

FIG. 1B is a schematic diagram showing an operation of processing a moldfor forming the microstructure shown in the FIG. 1A;

FIG. 2A is a schematic diagram showing a backlight module in accordancewith a first embodiment of the present invention;

FIG. 2B is a structural diagram showing a light guide plate inaccordance with the first embodiment of the present invention;

FIG. 3A is a schematic diagram showing a backlight module in accordancewith a second embodiment of the present invention;

FIG. 3B is a structural diagram showing a light guide plate inaccordance with the second embodiment of the present invention;

FIG. 4 is a schematic diagram showing a backlight module in accordancewith a third embodiment of the present invention;

FIG. 5 is a schematic diagram showing a backlight module in accordancewith a fourth embodiment of the present invention;

FIG. 6 is a schematic partial structural diagram showing a light guideplate in accordance with a fifth embodiment of the present invention;

FIG. 7 is a schematic partial structural diagram showing a light guideplate in accordance with a sixth embodiment of the present invention;and

FIG. 8 is a schematic diagram showing a display device in accordancewith an embodiment of the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to the present embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers are used in thedrawings and the description to refer to the same or like parts.

Simultaneously referring to FIG. 2A and FIG. 2B, FIG. 2A and FIG. 2B arerespectively a schematic diagram showing a backlight module 100 and astructural diagram showing a light guide plate 120 in accordance with afirst embodiment of the present invention. The backlight module 100 ofthe present embodiment mainly includes a light source 110 and the lightguide plate 120. The light guide plate 120 has a main body 121, pluralstripe structures 122 and plural light-adjusting structures 123. Themain body 121 has a light-incident surface 121 a and optical surfaces,such as a reflective surface 121 b, a light-emitting surface 121 c andan opposite light-incident surface 121 d. The light-incident surface 121a is opposite to the opposite light-incident surface 121 d, and thereflective surface 121 b and the light-emitting surface 121 c arerespectively connected to two opposite sides of the light-incidentsurface 121 a. The light source 110 is disposed adjacent to thelight-incident surface 121 a of the light guide plate 120 and is used toprovide light beam to the light guide plate 120.

Continuously referring to FIG. 2A and FIG. 2B, in the presentembodiment, the stripe structures 122 are disposed on the reflectivesurface 121 b, and an extending direction of the stripe structures 122is vertical to an extending direction of the light-incident surface 121a. Each of the stripe structures 122 extends from the light-incidentsurface 121 a to the opposite light-incident surface 121 d. In otherwords, one end of each of the stripe structures 122 is connected to thelight-incident surface 121 a, and the other end of each of the stripestructures 122 is connected to the opposite light-incident surface 121d. In the present embodiment, the stripe structures 122 are continuouslyarranged along a direction which is parallel to the extending directionof the light-incident surface 121 a.

As shown in FIG. 2A and FIG. 2B, the light-adjusting structures 123 aredisposed between every two adjacent stripe structures 122. In thepresent embodiment, the stripe structures 122 and the light-adjustingstructures 123 are convex structures. Each of the light-adjustingstructures 123 has a first light active surface 123 a and a second lightactive surface 123 b, in which the second light active surface 123 b isconnected to the first light active surface 123 a, and side edges of thefirst light active surface 123 a and the second light active surface 123b of each of the light-adjusting structures 123 are connected tosurfaces of the stripe structures 122 which are adjacent to thelight-adjusting structures 123. As shown in FIG. 2A, the first lightactive surface 123 a and the second light active surface 123 b of eachof the light-adjusting structures 123 are connected to form a junctionline 123 c, and a distance between the junction line 123 c of each ofthe light-adjusting structures 123 and the reflective surface 121 b isconsistent from the light-incident surface 121 a to the oppositelight-incident surface 121 d. More specifically, each of the stripestructures 122 has a line 122 a and two faces (i.e. face 122 b and face122 c), the face 122 b faces the light-incident surface 121 a and theface 122 c faces the opposite light-incident surface 121 d. The line 122a is a tangent line which is tangent to and connected to the faces 122 band 122 c. In one embodiment, the lines 122 a of all of the stripestructures 122 are located on a same plane. A distance between thejunction line 123 c of each of the light-adjusting structures 123 andthe plane where the stripe structures 122 are located is consistent fromthe light-incident surface 121 a to the opposite light-incident surface121 d. In other words, each of the light-adjusting structures 123 hassame height. The first light active surface 123 a and the second lightactive surface 123 b are inclined towards different directions andformed a non-symmetrical shape. The first light active surface 123 afaces towards the light-incident surface 121 a and is inclined relativeto the reflective surface 121 b, and a first included angle α 1 isformed between the first light active surface 123 a and the reflectivesurface 121 b. The second light active surface 123 b faces towards theopposite light-incident surface 121 d and is inclined relative to thereflective surface 121 b, and a second included angle β1 is formedbetween the second light active surface 123 b and the reflective surface121 b. Both the first included angle α1 and the second included angle β1are acute angles. In some present embodiments, the first included angleα1 is different from the second included angle β1. In other words, eachof the light-adjusting structures 123 has an asymmetric triangle shapewhen viewed from a side (as shown in FIG. 2A). In the presentembodiment, the first included angle α1 is greater than the secondincluded angle β1. Therefore, most of the light entering the light guideplate 120 from the light-incident surface 121 a is emitted towards thesecond light active surface 123 b and is further reflected by the secondlight active surface 123 b. In other words, the second light activesurface 123 b is a surface which receives light directly. In thestructural design of each of the light-adjusting structures 123, an areaof the second light active surface 123 b is greater than an area of thefirst light active surface 123 a, so as to increase the amount of lightreflection, thereby increasing light utilization efficiency. Inaddition, side edges of each of the light-adjusting structures 123 areconnected to surfaces of adjacent stripe structures 122, such that thestripe structures 122 are formed as side portions of the light-adjustingstructures 123, thereby preventing the light leakage problem on thesides of the conventional microstructures. In other words, thelight-adjusting structures 123 are directly connected to the stripestructures 122 instead of being connected to the light-emitting surface121 c or the reflective surface 121 b of the light guide plate 120, thusresolving the light leakage problem due to the connections between theconvention microstructures and the flat optical surface (such aslight-emitting surface or reflective surface of the light guide plate)as described in the “Description of Related Art”.

It is noted that, the stripe structures and the light-adjustingstructures which are convex structures are merely used as an example forexplanation, and embodiments of the present invention are not limitedthereto. In other embodiments, the light guide plate has differentdesigns. Referring to FIG. 3A and FIG. 3B, FIG. 3A and FIG. 3B. 2B arerespectively a schematic diagram showing a backlight module 200 and astructural diagram showing a light guide plate 220 in accordance with asecond embodiment of the present invention. As shown in FIG. 3A, thebacklight module 200 of the present embodiment mainly includes a lightsource 110 and the light guide plate 220. The light guide plate 220 ofthe present embodiment has a main body 221, plural stripe structures 222and plural light-adjusting structures 223. The main body 221 has alight-incident surface 221 a, a reflective surface 221 b, alight-emitting surface 221 c and an opposite light-incident surface 221d.

Referring to FIG. 3B, the stripe structures 222 are disposed on thereflective surface 221 b. In the present embodiment, the light-adjustingstructures 223 are disposed between every two adjacent stripe structures222, and the stripe structures 222 and the light-adjusting structures223 are concave structures. The design of the light-adjusting structures223 in the present embodiment is similar to that of the aforementionedlight-adjusting structures 123. Each of the light-adjusting structures223 has a first light active surface 223 a and a second light activesurface 223 b, and the first light active surface 223 a faces towardsthe light-incident surface 221 a, and the second light active surface223 b faces towards the opposite light-incident surface 221 d. The firstlight active surface 223 a and the second light active surface 223 b areinclined towards different directions and formed a non-symmetricalshape. In other words, the first light active surface 223 a and thesecond light active surface 223 b are inclined relative to thereflective surface 221 b at different angles. Moreover, the area of thesecond light active surface 223 b which receives light directly can bedesigned to be greater than the area of the first light active surface223 a, so as to increase the amount of light reflection, therebyincreasing light utilization efficiency. As shown in FIG. 3A, the firstlight active surface 223 a and the second light active surface 223 b ofeach of the light-adjusting structures 223 are connected to form ajunction line 223 c, and a distance between the junction line 223 c ofeach of the light-adjusting structures 223 and the reflective surface221 b is consistent from the light-incident surface 221 a to theopposite light-incident surface 221 d. In other words, each of thelight-adjusting structures 223 has same depth. In addition, the sideedges of each of the light-adjusting structures 223 are connected to thesurfaces of the adjacent stripe structures 222, so that the stripestructures 222 are formed as side portions of the light-adjustingstructures 223, thus preventing the light leakage problem on the sidesof the conventional microstructures. In other words, the light-adjustingstructures 223 are directly connected to the stripe structures 222instead of being connected to the flat optical surface (i.e.Light-emitting surface 221 c or the reflective surface 221 b) of thelight guide plate 220, thus resolving the light leakage problem due tothe connections between the convention microstructures and the flatoptical surface of the light guide plate as described in the“Description of Related Art”. Moreover, since the adjusting structures223 are concave structures, tips of the adjusting structures 223 arelocated inside of the stripe structures 222, which can reduce a contactarea between the light guide plate 220 and the reflecting film locatedunder the light guide plate 220, so as to avoid the occurrence ofadsorption between the reflecting film and the light guide plate 220.Moreover, while traveling inside the light guide plate 220, the lightbeam is not interfered by the transition of the light-adjustingstructures 223, and the area of the second light active surface 223 bwhich receives light can be designed to be larger, which can effectivelyimprove the overall luminance of the light guide plate 220.

In the aforementioned embodiments, the light-adjusting structures whichhave the same size and are non-continuously arranged are not used tolimit the present invention. In other embodiments, the size of each ofthe light-adjusting structures can be designed according to the distancebetween each of the light-adjusting structures and the light-incidentsurface. Referring to FIG. 4 , FIG. 4 is a schematic diagram showing abacklight module 300 in accordance with a third embodiment of thepresent invention. The structure of the backlight module 300 of thepresent embodiment is similar to that of the backlight module 100 shownin FIG. 2A, and the main difference therebetween is that a light guideplate 320 of the backlight module 300 has different designs.

Continuously referring to FIG. 4 , the light guide plate 320 includes amain body 321, plural stripe structures 322 and plural light-adjustingstructures 323. In the present embodiment, the stripe structures 322 aredisposed on the main body 321, in which an extending direction of thestripe structures 322 is vertical to a light-incident surface 321 a ofthe main body 321. In the present embodiment, the stripe structures 322are convex structures, and the light-adjusting structures 323 aredisposed between and along the stripe structures 322. In addition, thedesign of the light-adjusting structures 323 are the similar to that ofthe aforementioned light-adjusting structures 123 and 223, and thereforewill not be described again herein.

As shown in FIG. 4 , in the present embodiment, each of thelight-adjusting structures 323 has a size which becomes greater withincreased distance from the light-incident surface 321 a. In otherwords, sizes of the light-adjusting structures 323 located away from thelight-incident surface 321 a are greater than sizes of thelight-adjusting structures 323 located near the light-incident surface321 a, thereby increasing the amount of light emitted from a location ofthe light guide plate 320 which is away from the light-incident surface321 a and increasing the overall light uniformity of the light guideplate 320.

In the aforementioned embodiment, a pitch between two adjacentlight-adjusting structures can be designed according to distancesbetween the light-adjusting structures and the light-incident surface.Referring to FIG. 5 , FIG. 5 is a schematic diagram showing a backlightmodule 400 in accordance with a fourth embodiment of the presentinvention. The structure of the backlight module 400 of the presentembodiment is similar to that of the backlight module 100 shown in FIG.2A, and the main difference therebetween is that a light guide plate 420of the backlight module 400 has different designs.

Referring to FIG. 5 again, the light guide plate 420 includes a mainbody 421, plural stripe structures 422 and plural light-adjustingstructures 423. In the present embodiment, the stripe structures 422 aredisposed on the main body 421. An extending direction of the stripestructures 422 is vertical to a light-incident surface 421 a of the mainbody 421. In the present embodiment, the stripe structures 422 areconvex structures, and the light-adjusting structures 423 are disposedbetween and along the stripe structures 422. In addition, the design ofthe light-adjusting structures 423 are the similar to that of theaforementioned light-adjusting structures 123 and 223, and thereforewill not be described again herein.

As shown in FIG. 5 , in the present embodiment, pitches between everytwo adjacent light-adjusting structures 423 decrease along a directionfrom the light-incident surface 421 a to an opposite light-incidentsurface 421 a away from the light-incident surface 421 a. The “pitch”refers to a distance between two adjacent light-adjusting structures 423which is parallel to the extending direction of the stripe structures422. In other words, a pitch P2 between every two adjacentlight-adjusting structures 423 which are away from the light-incidentsurface 421 a is smaller than a pitch P1 between two adjacentlight-adjusting structures 423 which are near the light-incident surface421 a. Therefore, by densely arranging the light-adjusting structures423 on a portion of the light guide plate 420 which is away from thelight-incident surface 421 a, the amount of light emitted from theportion of the light guide plate 420 away from the light-incidentsurface 321 a and the overall light uniformity of the light guide plate420 can be increased accordingly.

In the aforementioned embodiment, the stripe structures are continuouslyarranged along the light-incident surface. In other embodiments, thestripe structures are non-continuously arranged along the light-incidentsurface. Referring to FIG. 6 , FIG. 6 is a schematic partial structuraldiagram showing a light guide plate 500 in accordance with a fifthembodiment of the present invention. The light guide plate 500 includesa main body 510, plural stripe structures 520 and plural light-adjustingstructures 530. An extending direction of the tripe structures 520 isvertical to a light-incident surface 511 of the main body 510. In thepresent embodiment, the stripe structures 520 are non-continuouslyarranged along a direction which is parallel to the light-incidentsurface 511. In other words, a distance G1 is formed between everyadjacent two stripe structures 520, and because a width of each of thestripe structures 520 is consistent from one end near the light-incidentsurface 511 to the other end away from the light-incident surface 511,the distance G1 has a constant width.

As shown in FIG. 6 , the light-adjusting structures 530 are disposedbetween every two adjacent stripe structures 520. In addition, each ofthe light-adjusting structures 530 has a first light active surface 531and a second light active surface 532, and the first light activesurface 531 faces towards the light-incident surface 511, and the secondlight active surface 532 faces away from the light-incident surface 511.In the present embodiment, the first light active surface 531 and thesecond light active surface 532 of each of the light-adjustingstructures 530 are continuously arranged along a direction which isvertical to the light-incident surface 511. The first light activesurface 531 and the second light active surface 532 of each of thelight-adjusting structures 530 are connected to form a junction line533, and each of the junction lines 533 is parallel to thelight-incident surface 511. In addition, each of the first light activesurfaces 531 has an end edge 531 a and two side edges 531 b, in whichthe end edge 531 a is parallel to the junction line 533, and the sideedges 531 b are not parallel to the junction line 533 and are directlyconnected to the surfaces of the adjacent stripe structures 520.Similarly, each of the second light active surfaces 532 has an end edge532 a and two side edges 532 b, in which the end edge 532 a is parallelto the junction line 533, and the side edges 532 b are not parallel tothe junction line 533 and are directly connected to the surfaces of theadjacent stripe structures 520. Therefore, at least one portion of eachof the light-adjusting structures 530 overlaps with the adjacent stripestructures 520. More specifically, two opposite side portions of each ofthe light-adjusting structures 530 are directly connected (jointed) tothe adjacent stripe structures 520, such that the light leakage problemdue to the connections between the convention microstructures and theflat optical surface of the light guide plate as described in the“Description of Related Art” does not occur. On the other hand, thedesign principles of the first light active surface 531 and the secondlight active surface 532 are respectively similar to the designprinciples of the aforementioned first light active surface 123 a and223 a and the second light active surface 123 b and 223 b. The firstlight active surface 531 and the second light active surface 532 areinclined at different angles, and the area of the second light activesurface 532 which directly receives light can be designed to be greaterthan the area of the first light active surface 531, so as to increasethe amount of light reflection, thereby increasing light utilizationefficiency.

It is noted that, in the present embodiment, each of the light-adjustingstructures 530 has a size which becomes greater increased distance fromthe light-incident surface 511, and the size is irrelevant to thedistance G1 between the adjacent two stripe structures 520. In a case ofa light guide plate which only has stripe structures, a phenomenon ofregular bright and dark stripes is likely occurred on the light guideplate due to the constant distance G1 between the adjacent stripestructures. Therefore, the light-adjusting structures of the presentinvention are used to be disposed between every two adjacent stripestructures to cut off the bright and dark stripes, thereby achieving auniform light effect. Moreover, each of the light-adjusting structures530 has a size which becomes greater with increased distance from thelight-incident surface 511. Therefore, for an area of the light guideplate with weaker brightness away from the light-incident surface 511,the light-adjusting structures 530 with greater size can guide morelight out of the light guide plate. Compared with an area of the lightguide plate with stronger brightness near the light-incident surface511, the light-adjusting structures 530 with smaller size can guide lesslight out of the light guide plate. Accordingly, different sizes of thelight-adjusting structures 530 can improve the light uniformity of thelight guide plate. On the other hand, by overlapping the light-adjustingstructures with the adjacent stripe structures, the light leakageproblem from the connections between the side portions of thelight-adjusting structures and a flat optical surface of the light guideplate can be resolved.

Referring to FIG. 7 , FIG. 7 is a schematic partial structural diagramshowing a light guide plate 600 in accordance with a sixth embodiment ofthe present invention. The light guide plate 600 of the presentembodiment includes a main body 610, plural stripe structures 620 andplural light-adjusting structures 630. An extending direction of thestripe structures 620 is vertical to a light-incident surface 611 of themain body 610. In the present embodiment, a width W1 each of the stripestructures 620 is gradually decreasing from one end each of the stripestructures 620 located near the light-incident surface 611 to the otherend of each of the stripe structures 620 located away from thelight-incident surface 611. Therefore, distances G2 between side edgesof two adjacent stripe structures 620 can be varied rather than beingfixed, thereby decreasing the chance of the occurrence of the regularlight and dark stripes on the light guide plate 600.

In the present embodiment, the light-adjusting structures 630 aredisposed between every two adjacent stripe structures 620. Moreover,each of the stripe structures 620 has a width W1 which decreases fromone end near the light-incident surface to the other end away from thelight-incident surface 611, such that the distance G2 between the sideedges of every two adjacent stripe structures 620 becomes greater. Forexample, as shown in FIG. 7 , each of the oblique line areas has a wideend and a narrow end, and the wide end is away from the light-incidentsurface 611. Each of the light-adjusting structures 630 has a size whichbecomes greater with increased distance from the light-incident surface611, such that widths of each of end edges 631 a and 632 a of each ofthe light-adjusting structures 630 become wider. In other words, in thepresent embodiment, each of the light-adjusting structures 630 has asize which becomes greater with increased distance from thelight-incident surface 611, and the size of each of the light-adjustingstructures 630 is relevant to the distance G2 between the stripestructures 620. For example, as shown in FIG. 7 , the size of thelight-adjusting structure 630 located near the light-incident surface611 is smaller than that of the light-adjusting structure 630 locatedaway from the light-incident surface 611.

Referring to FIG. 7 , each of the light-adjusting structures 630 has afirst light active surface 631 and a second light active surface 632,and the first light active surface 631 faces towards the light-incidentsurface 611, and the second light active surface 632 faces away from thelight-incident surface 611. In the present embodiment, the first lightactive surface 631 and the second light active surface 632 of each ofthe light-adjusting structures 630 are continuously arranged along adirection which is vertical to the light-incident surface 611. The firstlight active surface 631 and the second light active surface 632 of eachof the light-adjusting structures 630 are connected to each other toform a junction line 633 which is parallel to the light-incident surface611. In addition, each of the light-adjusting structures 630 has a firstflank portion 630 a and a second flank portion 630 b which arerespectively located at two opposite sides of the junction line 633 andare overlapped on the adjacent stripe structures 620. In other words,the first flank portion 630 a and the second flank portion 630 b of eachof the light-adjusting structures 630 are directly connected to thestripe structures 620, thus resolving the light leakage problem due tothe connections between the convention microstructures and the flatoptical surface of the light guide plate as described in the“Description of Related Art”.

In addition, in the embodiment of FIG. 6 and FIG. 7 , because each ofthe light-adjusting structures has the first flank portion and thesecond flank portion respectively extending from two opposite sides ofthe junction line, and lengths of the end edges are shorter than alength of the junction line of each of the light-adjusting structures,so that each of the first light active surface and the second lightactive surface is formed in trapezoid. If the light-adjusting structuresdo not have the design of the first flank portion and the second flankportion and a length of end edge is equal to the junction line, thefirst light active surface and the second light active surface are inshape of rectangular. Because the area of trapezoid is greater than thearea of rectangular shape, the trapezoid first light active surface andthe trapezoid second light active surface can reflect more light,thereby increasing light utilization efficiency.

On the other hand, the design principles of the first light activesurface 631 and the second light active surface 632 are respectivelysimilar to the design principles of the aforementioned first lightactive surface 123 a and 223 a and the second light active surface 123 band 223 b. The first light active surface 631 and the second lightactive surface 632 are inclined at different angles, and the area of thesecond light active surface 632 which directly receives light can bedesigned to be greater than the area of the first light active surface631, so as to increase the amount of light reflection, therebyincreasing light utilization efficiency. In addition, each of thelight-adjusting structures 630 has a size which becomes greater withincreased distance from the light-incident surface 611, so that the areaof the second light active surface 632 of one of the light-adjustingstructures 630 which is away from the light-incident surface 611 isgreater than the area of the second light active surface 632 of one ofthe light-adjusting structures 630 which is near the light-incidentsurface 611, such that the amount of light reflection emitted from aportion of the main body 610 away from the light-incident surface 611can be increased, thereby increasing light utilization efficiency.

Referring to FIG. 8 , FIG. 8 is a schematic diagram showing a displaydevice 700 in accordance with an embodiment of the present invention.The display device 700 of the present embodiment includes the backlightmodule 100 as shown in FIG. 2A, a display panel 710, at least one film720 and a reflecting film 730. As shown in FIG. 8 , the film 720 isdisposed in front of the light guide plate 120 of the backlight module100, and the reflecting film 730 is disposed behind the light guideplate 120 of the backlight module 100. The display panel 710 is disposedat a light emitting side of the light guide plate 120 of the backlightmodule 100. Therefore, by applying the light guide plate 120 having thedesign of the stripe structures 122 and the light-adjusting structures123 o to the display device 700 can increase the utilization efficiencyof light which is provided by the light source 110 and enters the lightguide plate 120. It is noted that, the backlight module 100 shown inFIG. 2A is merely used as an example which can be applied to the displaydevice 700 for explanation, and embodiments of the present invention arenot limited thereto. In other embodiments, other backlight modules, suchas the backlight modules having the light guide plate 200, 500 or 600,or the backlight module 300, or the backlight module 400 in otheraforementioned embodiments also can be applied to a display device, soas to achieve the same effect.

According to the aforementioned embodiments of the present invention,the light guide plate of the present invention has stripe structures andlight-adjusting structures disposed between every two adjacent stripestructures, such that the stripe structures are directly formed as sideportions of the light-adjusting structures, thereby preventing the lightleakage problem on the sides of the conventional microstructures. Inother words, because each of the light-adjusting structures is notdirectly connected to the flat surface of the light guide plate, thelight leakage problem due to the connections between the conventionmicrostructures and the flat optical surface of the light guide plate asdescribed in the “Description of Related Art” can be resolved. Inaddition, the light active surfaces of each of the light-adjustingstructures have different inclinations, which can increase the amount oflight reflection or guide the light, thereby increasing lightutilization efficiency. Because the stripe structures are directlyformed as side portions of the light-adjusting structures, theprocessing time of the light guide plate can be reduced, and theinclination of the light active surfaces can be precisely controlled,thereby achieving required optical effect.

Although the present invention has been described in considerable detailwith reference to certain embodiments thereof, other embodiments arepossible. Therefore, the spirit and scope of the appended claims shouldnot be limited to the description of the embodiments contained herein.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims.

What is claimed is:
 1. A light guide plate, comprising: a main bodycomprising a light-incident surface, an opposite light-incident surfaceand an optical surface, wherein the opposite light-incident surface isopposite to the light-incident surface, and an optical surface isconnected to the light-incident surface and the opposite light-incidentsurface; a plurality of stripe structures disposed on the opticalsurface and extending from the light-incident surface to the oppositelight-incident surface; and a plurality of light-adjusting structuresdisposed between every two adjacent stripe structures; wherein thelight-adjusting structures are arranged along a first direction which isvertical to the light-incident surface; wherein an occupy ratio of thelight-adjusting structures to the optical surface in a cross sectionalview parallel to the first direction is getting larger in response tothe distance which is away from the light-incident surface.
 2. The lightguide plate of claim 1, wherein a base length of each of thelight-adjusting structures is parallel to the first direction andgetting larger in response to the distance which is away from thelight-incident surface.
 3. The light guide plate of claim 1, wherein apitch which is between any two adjacent the light-adjusting structuresand parallel to the first direction is getting larger in response to thedistance which is away from the light-incident surface.
 4. The lightguide plate of claim 1, wherein a distance is formed between everyadjacent two stripe structures, and a width of each of the stripestructures is consistent from one end near the light-incident surface tothe other end away from the light-incident surface, such that thedistance has a constant width.
 5. The light guide plate of claim 1,wherein each of the stripe structures has a width which decreases fromone end near the light-incident surface to the other end away from thelight-incident surface, such that the distance between every twoadjacent stripe structures becomes greater.
 6. The light guide plate ofclaim 1, wherein each of the light-adjusting structures comprises afirst light active surface and a second light active surface connectedto the first light active surface, and the first light active surfacefaces towards the light-incident surface, and the second light activesurface faces towards a side of the main body which is opposite to thelight-incident surface, wherein the first light active surface and thesecond light active surface are inclined towards different directionsand formed a non-symmetrical shape.
 7. The light guide plate of claim 6,wherein a first included angle is formed between the first light activesurface and the optical surface, and a second included angle is formedbetween the second light active surface and the optical surface, whereineach of the first included angle and the second included angle is anacute angle.
 8. The light guide plate of claim 7, wherein the firstincluded angle is greater than the second included angle.
 9. The lightguide plate of claim 1, wherein the striped structures are convexstriped structures or concave striped structures.
 10. A backlightmodule, comprising: a light guide plate as claimed in claim 1; at leastone film disposed in front of the light guide plate; a reflecting filmdisposed behind the light guide plate; and a light source disposedadjacent to the light-incident surface of the light guide plate.
 11. Adisplay device, comprising: a light guide plate as claimed in claim 1;at least one film disposed in front of the light guide plate; areflecting film disposed behind the light guide plate; and a lightsource disposed adjacent to the light-incident surface of the lightguide plate; and a display panel disposed in front of the at least onefilm.